Charlize Theron, Mary J. Blige, and More Celebs Put on Their Ball Gowns for a Good Cause

Charlize Theron, Sean Penn, Mary J. Blige, and other A-list celebs descended upon Vienna, Austria, this past weekend to attend the Life Ball, one of the world's largest charity events for HIV/AIDS.

The night was all about celebrating life, love, and, of course, eradicating HIV/AIDS. "Growing up in South Africa, I saw the devastation of AIDS at young age. This disease has shaped my country," said Theron, whose Africa Outreach Project helps educate African youth to prevent the disease. "So, we're here, we're fighting in unity, we're making momentum, and we're here to celebrate the commitment of life to raise awareness and resources." Added Blige, a longtime supporter of AmfAR, "I'm overwhelmed with love and support with everyone here." She later sang U2's One at the event.

Kelly Osbourne, who presided over the Fashion Award for Best Costume, shared how the disease has affected her and members of her family. "[We want to] make this generation the last generation to suffer for this," she said.

The event, which included a weekend of effervescent parties and decadent dinners in Vienna, culminated in a quintessentially Austrian ball (in a castle!). This year's theme was gold, so attendees were practically gilded, from embellished gold gowns to head-to-toe body paint. Check out scenes from the celebration: